The Study Of Measurement Of Pulmonary Tumors Perfusion In First Pass Phase By Dynamic CT And Its Clinical Application

Objective To establish the best technique parameters of CT perfusion imaging in normal pulmonary parenchyma, and to evaluate pulmonary parenchyma perfusion of normal Chinese; Peripheral\central bronchial carcinomas and unilateral lung metastasis tumors by means of perfusion and peak enhancement value using dynamic contrast-enhanced multislice CT are characterized; To measure the maximal enhancement value and perfusion value of lung parenchyma which was around pulmonary tumors by using multi-slice spiral CT perfusion scanning ,and to compare with contralateral normal lung parenchyma, to explore the manifestations of para-tumor pulmonary perfusion in peripheral\central bronchial carcinomas and unilateral lung metastasis tumors. Materials and Methods (1) By applying a nuclear medicine data processing technique to the time-density data obtained from dynamic CT, pulmonary parenchyma perfusion was performed in 60 cases of normal Chinese which was divided in 3 average groups based on the injection velocity. A single level through the hilum of lung and pulmonary artery was scanned after the intravenous injection of 40 ml of contrast given atN 4ml/s or 5ml/s .Thirty 0.5s duration and 0.5s interval scans were performed from 0 to 30s after injection. Time-density curves were then drawn from both lung and pulmonary artery using regions of interest (ROIs). Following previous work, pulmonary parenchyma perfusion was calculated as the peak upslope of the tissue time-density curve divided by peak pulmonary artery enhancement. (2) 92 patients included 48 Peripheral bronchial carcinomas, 31 central bronchial carcinomas and 13 unilateral lung metastasis tumors were examined. Density-time curves were evaluated from regions of interest of the whole tumor and high- and low-enhancing tumor areas. Perfusion and peak enhancement were calculated using the maximum-slope method of Miles and compared with size, localization (central or peripheral) and histology. (3) 92 patients mentioned in part II were studied. Density-time curves were evaluated from regions of interest of para-tumor lung parenchyma and contralateral normal lung parenchyma. Perfusion, peak enhancement and peak time were calculated using the maximum-slope method of Miles and compared that of the two.Results (1) Pulmonary parenchyma perfusion of normal Chinese with the injection velocity 3ml/s -> 4ml/s and 5ml/s respective was \A\±0.26(X±S) ml/min/ml, (1.01±0.14) ml/min/ml , (1.08±0.12) ml/min/ml, The difference of the perfusion between 3ml/s and 4ml/s or 5ml/s is marked statistical significance, and the difference between latertwo is no statistical significance. (2) Perfusion and peak enhancement value of large tumors (diameter >4 cm) averaged over either the whole tumor and the highest or the lowest enhancing area was significantly lower than that of smaller ones(diameter^4cm). Independent of size, either the whole tumor and the highest or the lowest enhancing area as the ROI (region of interest), central carcinomas had a significantly (p<0.05) lower perfusion (mean 0.39 ml/min/ml) than peripheral ones (mean 0.73 ml/min/ml), In contrast, peak enhancement of central and peripheral carcinomas was also significantly different; central carcinomas had a significantly (p<0.05) lower perfusion and peak enhancement value than unilateral lung metastasis tumors (mean 0.76 ml/min/ml), and peripheral ones did not. Between non-small-cell lung cancers and small-cell lung cancers, no significant differences were observed in both parameters. (3) In peripheral lung cancer group, para-tumor lung parenchyma had a significantly lower perfusion value ,enhancement peak value and peak time than that of contralateral normal lung parenchyma(Pl,P2,P3<0.0001); In central bronchial carcinomas group, para-tumor lung parenchyma had a significantly lower perfusion value enhancement peak value and peak time than that of contralateral normal lung parenchyma (Pl,P2,P3<0.0001); In unilateral lung metastasis tumor group, the difference of perfusion value , enhancement peak value and peak time between para-tumor lung parenchyma and contralateral...